Double pole electromagnetic switching device



March 18, 1958 w. DE FLIGUE DOUBLE POLE ELECTROMAGNETIC SWITCHING DEVICE Filed March 18, 1955 2 Sheets-Sheet 1 DOUBLE POLE ELECTROMAGNETIC SWITCHING DEVICE Filed March 1a, 1955 March 18 1958 w. DE FLIGUE 2 Sheets-Sheet 2 United States Patent DOUBLE POLE ELECTROMAGNETIC SWITCHING DEVICE Wladimir de Fligu, Paris, France Application March 18, 1955, Serial No. 495,250

6 Claims. (Cl. 20093) Relays or contactors having double pole double throw contacts are commonly provided and operate satisfactorily where there is sufficient power that they operate on the all or nothing principle, that is to say, when their coils are either fed or not fed.

Circumstances are entirely diiferent when the current unequal wear thereon, and because the contacts must not rebound one from the other as they are closed.

The known double pole double throw relays, for ex-' ample relays of the telephone type, comprise contact supports having resilient blades. Such relays lack sensitivity and precision because the instant at which the circuit breaks is not clearly defined because of the resiliency of the blades. Moreover, their circuit-breaking power is very low, because the contact pressure is determined substaritially by the resilience of the blades.

The present invention has for its object to provide an improved double pole double throw relay or contactor which provides for substantially simultaneous closing and opening of the pairs of contacts, an appreciable contact pressure and, finally, high accuracy of operation, while ensuring that the armature is attracted and released with sudden movement, even with progressive increasing or decreasing in the exciting current.

According to this invention there is provided an armature of fiat elongated form which is moved by the electromagnet against the force of a return device, the armature supporting, outside its plane, at least two movable contacts which co-act with two fixed contacts and said armature being arranged to pivot about two axes perpendicular to one another, one axis being transverse to the said armature and situated substantially in the plane of the latter and the other axis being substantially perpendicular to the plane of the armature.

Preferably the armature has its plane face in contact with a straight edge of an immovable part of the device which acts as a hinge, the armature being provided on the one hand with means to enable it to pivot in said plane face and, on the other hand, with two rigid extensions substantially perpendicular to, and to one side of, said face which extensions carry the movable contacts.

Practical applications of the invention will now be described, by way of example only, with reference to the accompanying drawings whereof:

Fig. 1 is a diagrammatic perspective view of a device according to the invention. 7

Figs. 2 and 3 are vertical sections showing certain details of construction of the device of Fig. 1.

Figs. 4 and 5 are plan and side views respectively of 2,827,529 Patented Mar. 18, 1958 ice a practical construction of armature according to this invention.

Fig. 6 is a perspective view of relay according to the invention incorporating the armature shown in Figs. 4 and 5.

Fig. 7 is a front view of a flexible electrical connection comprising part of the device of Fig. 6, and

Fig. 8 is perspective view of an alternating construction of member shown in Fig. 7.

The relay, shown in Fig. 1 comprises a stirrup or U- shaped member 1 between the arms of which is the magnetic core 2 which supports the coil 3, the connections to which are indicated at 4.

Arranged to pivot about the straight edge 1a of the member 1 is the armature 5, the inner face of which is plane at least in the neighbourhood of the edge 1a.

Said edge and face combine to form the pivoting axis The armature 5 is subjected to a return force from a permanent magnet 6, which is carried by the member 1. Alternatively this return force may be provided by a spring. The armature supports, on the same side thereof, two insulating extensions 7a and 7b which are substantially perpendicular to the plane of the armature. On the ends of the extensions are the contact members 8a and 8b, which are shown as two small solid cylinders.

The ends of the moving-contact cylinders coact with fixed contact studs 9a, 10a in the case of the cylinder 8a and with the contact studs 9b, 10b in the case of the cylinder 8b. The contact members 8a, 8b are connected by the conductors 11a and 11b to terminals not shown, these conductors being pliable so that the armature 5 has complete freedom of movement.

There is secured to the electromagnet 1, 2, 3 a second permanent magnet 28 which acts on the armature 5 in opposition to the magnet 6. The provision of this permanent magnet is optional.

Let it be assumed that current is passed through the coil 3: when the attraction of the electromagnet 1, 2, 3 possibly in combination with the attraction of the magnet 28 overcomes the attraction of the magnet 6, the armature 5 pivots in the direction of the arrow F and the contact members 8a, 8b both move towards the studs 9a, 9b. Since it is substantially impossible to ensure simultaneous contact of the two members 8a and 8b with the fixed studs 9a and 9b, one of them, for example 8a, will be the first to touch the stud 9a. If the armature 5 is prevented from moving lengthwise, but can pivot in its plane while remaining in engagement with the edge 1a, the bearing reaction due to contact between 8a, 9a produces a movement which tends to turn the moving armature as a whole in the direction of the arrow G, for example about the axis Y-Y that is to say, in the direction which carries contact member 8b towards the stud 9b. A very short instant after 8a and 9a have come into contact, contact will be established between 8b and 9b. Because of the symmetrical arrangement of the extensions 7a and 7b in relation to the armature, if the centre about which the armature pivots in its plane is in the plane of symmetry of the armature, the contact pressure produced by attraction of the electromagnet and of the magnet 28, will be equally applied to the contact members.

When the exciting current in the coil 3 decreases, the attraction of the magnet 6 becomes preponderant and armature 5 pivots in the direction of the arrow F According to which of the contact members (8a, 8b) is the first to come into contact with the corresponding stud (10a, 10b), the moving armature is then urged to rotate in its plane until the two contact members practically simultaneously touch the two fixed studs.

Inboth cases, the studs 9a, 9b on the one hand and 10a; 10b on the-other hand -formabutments'limiting the manent magnet. The danger of the moving armaturesticking in either one of its extreme positions is thus avoided, while in-"addition' the -edge ltd-"may be formed simply'by the contact between-the faces situated ata right-angle to the arm 11) of the stirrup-me'mbe'r l.

As maybe-seen from Fig 1,-the extensions 7a' and 7b are off set frorrrthe axis x'x so that themovernent of members Sea-8b abouttheaxis x x has'a verticalas-well as a horizontal component-i. e. the movement is 'slightly oblique.- Consequently, the moving contacts slidetoa small extentacross studs 9a, 9b; 10a, 10b wheri they'move towards or away from them.-

A- relay accordingto-the invention therefore comprises means for preventing translational movements of the armature in relation to an immovable part-'of 'the relay and for permittingthe armature to pivot inits-plane.

I One constructionof such means is shownin Fig.2a'- Let into the face is of the arm lb'of the stirrupsmember '1- is a rod 11 which passes through a recess in the armature 5 in the longitudinal plane of symmetryithereofgtheaxis'of the rod passinglthrough'axis.x-x. The recess-:isla hemi=- spherical socket 12 which receives a'ball 13'. screwedpfor example, to the upper end of the ;rod:1t and lockedithereto by a nut. This swivel joint, while allowing fonthe'slights play necessary, permits the-pivotingmovemenoabouttthe edge 3a, prevents translational movement: of-the-arma'tur'e in its planeand serves as a pivot" for the'ro'tation-ofthe; armature in this plane.

In order to reducefriction; this swivel-joint maysbe constructed as shown in Fig. 3. A'socliet member: 14. is

let into the armature 5 andthe rod 11 carriesa cone-15,--

balls 16 being disposed between the coneandthe socket; member.

Figs. 4 and 5 illustrate a practical arrangement of 'arm'ature with extensions: and contacts carried' thereby. .Two lugs 5a andSbof thearmatnre 5 'car ryfsaid extensions and replace thSECIOSS' member diagrammatically shown'imFig. l. Rigidly securedtothe'under-face of the lugsi ar'e T- shaped carriers of-insul-atingrmaterial and on-eachside of the carriers the blades? 2i} are'secured by rivetsi29. 'The' carriers referred toconstitute the extensions '8rr and-7I5 of Fig; l; An 'electrical connector"device 3t) 'ofU-shaped form as seen inplan view (Fig-:7) or bispiral formi-as seen in Fig; Sis secured to' one of theEcar-riers. together with:-

the blades 2i Theconnectorfitlacohsists of soft metal; which maybe annealed to ensurethat' it is readily; defo'rma able. Anarm fida of connector 'fh-is'gripped between the free ends Ztlticf the'blades itlgwhile'the corrugated secondarm 3iib=constitutes a very'flexible leaid inzconduc tor equivalent to the conductors 11a, 11b of Fig; l.

The friction ofthe" cranked portions-tzfia' against the portions 30a damps-movement- 'ofthe' armature while at the same time enabling.zgood 'electrical contact betweem the lead-inconcluctor and the bladesitl The blades-2d carry the-contactmemberszl- The con: tactstuds consists of screws 22= (see; alsoFig which are received in a sctewthreadedmember formed by;bend-' ing over a strip=23 The screw-thread is formed after the strip has been bent to the required shape, the bentover portions are heldjtogetherby' a-rivetfld; A fOIFiilEOf elastic nut is thus obtained-whieh preventsinadvertent rater tion of the screws 22; and;which; imaddition ensuresz: 1? good electrical contact; It isvthus pos'sinleto-"obtaj, an accurate and lastingzmicromet-ric adjustment of'the posi tions of the screwheads serving as 'cont'ae't studs Fig. 6 shows a cor'ripl'e te relay according to theinven tiou.

The electromag'net 1,- 2; 3 carries the additional'magnet 28 whichacts on thefree-end of the armature 5, the

In order'further to reduce any spring action of the;

conductor carried by armature 5 the device 30 may be replaced, as illustrated in Fig. 8, by a strip 31 of tempered metal, for example silver, of' sufficient length, which is coiled in thefo'rmof a double spiral. The end 31a of the strip is connected to a terminal 27 (Fig. 6), while the end 31b,- which' is in the form of a blade, is introduced between the ends 20 of the contact carrying blades 20.

With the arrangements described the armature is moved in one directionor the other either by the'attractive force of the electromagnet'or of the return permanent mag net with considerable acceleration so that a sudden movement is ensured even with small variations in the exciting current to the electromagnet." Sincethe armature moves rapidly ifoneset of"cont'ac'ts before the other the time interval between engagement is very small;

considerations apply during disengagement of the contacts. While the'armature moves rapidly precautions have been taken, asdescribed,to'prevent rebound at the contacts. V

The provision-of a permanent 'magnet which acts in the same sense as the'electromagnet' ensures that the movement of thearmature to'close'the contacts is further increase'd'and'als'o enables'the armature to be heldin the position'to which it is movedbythe'electromagnet, in the absence of an ener'gisingcurrent, without mechanical locking means. T o'movethe armature away from such locked position it "is necessary. to provide manual means or auxiliary electromagneticmeans.

WhatIclaimisz' V 1. A double pole electromagnetic switching device comprising a magnetic core having an endwith a sharp rectilinear edge, an elongated flat armature resting on said rectilinear edge'and adapted to pivot both about said edge and about an axis'therethrough perpendicular to said armature, two laterally extending arms fast with said armatureand 'h'avingend' portions spaced from the plane containing'said armature and onthe same side thereof, a contact member on each of said portions, and two stationary contact studs cooperating with said con tact members.

2. Device as 'claimed in'claim 1 comprising a swivel joint connecting the armature to the core whereby said armature is'pivotable about both the rectilinear edge and the axis therethrough perpendicular to said' armature.

3f Devicejas" claimed in claim whe'reindhe swivel joint comprises- 'a'pivot fast'with the coreand extendingperpendicularly to the rectilinear edge, and a cup-shaped socket housed within a recess in the armature.

4. Device as claimed in claiml furthercomprising an extension of the armature beyond the rectilinear edge, a permanent magnet fast with the coreand exterting attraction on saidextnsion, and a further permanent magnet fast with said core and exerting attraction; on; a portion Effectively. the two' sets of contacts engage simultaneously. Similar cooperating with a contact member, whereby said device is operable as a double pole double throw switch.

6. Device as claimed in claim 5 wherein the contact members on the same extension are interconnected by means of a resilient strip of tempered metal twisted to form two oppositely coiled spirals inside each other, whereby opposite and substantially equal stresses are created in said strip upon bending the same.

References Cited in the file of this patent UNITED STATES PATENTS 6 Hoge Feb. 3, Witt June 29, Atwood Apr. 1, Day Feb. 26, Wise Feb. 16, Beeman May 28, Humphreys et al. Mar. 4, Ray 1- May 19, McMasters et al. Aug. 6, Hall Jan. 11, Ray Oct. 9, Bernstein Feb. 22,

FOREIGN PATENTS France Apr. 28, 

